Underfeed-stoker



PATENTBD JAN. 12, 1904.

J SEARLE. UNDERFEED STOKER.

APPLIUATION FILED 001 .30, 1903.

H0 MODEL.

NAW

I No. 749,501.

Patented January 12, 1904.

PATENT OFFICE.

JOSEPH M. SEARLE, OF PITTSBURG, PENNSYLVANIA.

UNDERFEED-STOKER.

SPECIFICATION forming part of Letters Patent N0. 749,501, dated January 12, 1904.

Application filed October 30, 1903. Serial No. 179,224. (No model.)

To all whom it may concern.-

I Be it known that I, JOSEPH M. SEARLE, a citizen of the United States, and a resident of Pittsburg, Pennsylvania, have invented certain Improvements in Underfeed-Stokers, of

which the following is a specification.

The object of my invention is to improve the construction and operation of a stoker of the underfeed type, an object which I attain .1 by combining with the central trough or retort of the stoker hollow twyer-boxes mounted at their inner ends by means of a knucklejoint upon the upper edges of the trough or retort and supported at their outer ends upon the side walls or other fixed structure of the furnace, and preferably upon a twyer-pipe which supplies air or steam to the hollow twyer-boxes, so as to keep them cool and aid in supporting combustion, the twyer-boxes 2 being of suflicient extent to take the place of the usual twyer-boxes and the dead-plates or grate-bars flanking the same. In the accompanying drawings, Figure 1 is I i a transverse section of sufiicient of an under- 5 feed-Stoker to illustrate my present invention, I and Fig. 2 is a plan view of part of the same. In Fig. 1 of the drawings, 1 1 represent the side walls of the furnace, and 2 the central trough or retort, into the lower portion of which the coal is fed by any suitable means, combustion taking place at the top of said retort. The retort 2 is of U or V shape, and I each of its upper edges is rounded to form a rib 3, to which are fitted sockets 4 at the inner ends of the twyer-boxes 5, each of the latter consisting of a hollow elongated box terminating at its inner end in ports 6, below which is an inwardly-projecting rib 7, which directs away from said ports the upwardlyrising massof coal or other fuel in the retort 2 in order to prevent choking of said ports by the fuel. In the bottom of each twyer, at the inner end of the same, is an opening 8, which permits of the discharge of any ashes or fine particles of fuel which may find their way through the ports 6, thereby preventing the choking or obstruction of the twyer by accumulation of such ashes or fine particles of fuel therein.

The outer ends of the twyer-boxes 5 rest,

preferably, upon a twyer-pipe 9, one of these twyer-pipes being seated upon and confined to each of the side walls of the furnace, each twyer-box being in communication with its corresponding pipe through openings 10, 5 5 formed in said box and pipe, as shown in Fig. 1. Steam or air admitted to the twyerpipe therefore finds its way into the hollow twyer-boxes, is heated in its passage through the same, and finally escapes through the ports 6, so as to aid in supporting the combustion of the fuel at the top of the retort 2, the passage of the steam or air through the twyerboxes also serving to keep the same cool and prevent them, from being burned out by the 5 heat of the mass of incandescent fuel lying upon the same. The twyer-boxes thus serve the purpose of the usual twyerboxes and their flanking dead-plates or grate-bars and have the advantage of being more durable than either of the latter because of the abovenoted tendency to resist burning.

The rib 3 of the retort and the socket 4 of the twyer-box form a knuckle-joint, which looks together the inner end of the twyer-box 7 5 and the retort when said twyer-box is in the horizontal or operative position shown in Fig. 1, any of the twyer-boxes, however, being readily removed by lifting its outer end until it assumes a vertical position ora position approaching the vertical, which will permit its socket to be lifted from the rib 3 of the retort, the fitting of the twyer-box into position being effected by a reverse operation.

The twyer-pipes 9 and hollow twyer-boxes 5 5 serve as a convenient means for disposing of exhaust-steam and at the same time adding materially to the life of the twyers and deadplates.

Having thus described my invention, I claim and desire to secure by Letters Patent 1. An underfeed-stoker having a fuel trough or retort and twyer-boxes mounted by means of a knuckle-joint upon an upper edge of said trough or retort and supported at their outer 95 ends upon a side wall of the furnace through the medium of a longitudinal twyer-pipe, substantially as specified.

2. An underfeed-stoker comprising a fuel trough or retort, and hollow twyer-boxes rest- I00 ing at their inner ends upon an upper edge of said trough or retort and supported at their outer ends upon a twyer-pipe Which communicates with said tWyer-boxes, substantially as specified. V

3. An underfeed-stoker having a fuel trough or retort and hollow twyer-boxes mounted upon an upper edge of said retort and extending therefrom to a side Wall of the furnace so as to constitute combined twyer-boxes and dead-plates, substantially as specified.

4. Thecombination, in an underfeed-stoker, of a fuel trough or retort and hollow tWyerboxes mounted upon an upper edge of said retort and extending outwardly therefrom, each of said twyer-boxes having ports in its inner face, and a bottom opening, near the inner end, for the escape of matter entering the twyerbox through said ports, substantially as specified.

5. The combination, in an underfeed-stoker, of a fuel trough or retort, tWyer-b oxes mounted upon an upper edge of said retort and extending outwardly therefrom to a side Wall of the furnace, each of said twyer-boxes having ports in its inner face, and, below said ports, an inwardly-projecting fuel-deflecting rib, substantially as specified.

In testimony whereofIha e signed my name to this specification in the presence of tWo sub- 3 scribing Witnesses.

J. M. SEARLE.

Witnesses:

FRANK J. CRUM, DANL. A MoCun. 

